less/lib/less/visitors/visitor.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var tslib_1 = require("tslib");
var tree_1 = tslib_1.__importDefault(require("../tree"));
var _visitArgs = { visitDeeper: true };
var _hasIndexed = false;
function _noop(node) {
    return node;
}
function indexNodeTypes(parent, ticker) {
    // add .typeIndex to tree node types for lookup table
    var key, child;
    for (key in parent) {
        /* eslint guard-for-in: 0 */
        child = parent[key];
        switch (typeof child) {
            case 'function':
                // ignore bound functions directly on tree which do not have a prototype
                // or aren't nodes
                if (child.prototype && child.prototype.type) {
                    child.prototype.typeIndex = ticker++;
                }
                break;
            case 'object':
                ticker = indexNodeTypes(child, ticker);
                break;
        }
    }
    return ticker;
}
var Visitor = /** @class */ (function () {
    function Visitor(implementation) {
        this._implementation = implementation;
        this._visitInCache = {};
        this._visitOutCache = {};
        if (!_hasIndexed) {
            indexNodeTypes(tree_1.default, 1);
            _hasIndexed = true;
        }
    }
    Visitor.prototype.visit = function (node) {
        if (!node) {
            return node;
        }
        var nodeTypeIndex = node.typeIndex;
        if (!nodeTypeIndex) {
            // MixinCall args aren't a node type?
            if (node.value && node.value.typeIndex) {
                this.visit(node.value);
            }
            return node;
        }
        var impl = this._implementation;
        var func = this._visitInCache[nodeTypeIndex];
        var funcOut = this._visitOutCache[nodeTypeIndex];
        var visitArgs = _visitArgs;
        var fnName;
        visitArgs.visitDeeper = true;
        if (!func) {
            fnName = "visit" + node.type;
            func = impl[fnName] || _noop;
            funcOut = impl[fnName + "Out"] || _noop;
            this._visitInCache[nodeTypeIndex] = func;
            this._visitOutCache[nodeTypeIndex] = funcOut;
        }
        if (func !== _noop) {
            var newNode = func.call(impl, node, visitArgs);
            if (node && impl.isReplacing) {
                node = newNode;
            }
        }
        if (visitArgs.visitDeeper && node) {
            if (node.length) {
                for (var i = 0, cnt = node.length; i < cnt; i++) {
                    if (node[i].accept) {
                        node[i].accept(this);
                    }
                }
            }
            else if (node.accept) {
                node.accept(this);
            }
        }
        if (funcOut != _noop) {
            funcOut.call(impl, node);
        }
        return node;
    };
    Visitor.prototype.visitArray = function (nodes, nonReplacing) {
        if (!nodes) {
            return nodes;
        }
        var cnt = nodes.length;
        var i;
        // Non-replacing
        if (nonReplacing || !this._implementation.isReplacing) {
            for (i = 0; i < cnt; i++) {
                this.visit(nodes[i]);
            }
            return nodes;
        }
        // Replacing
        var out = [];
        for (i = 0; i < cnt; i++) {
            var evald = this.visit(nodes[i]);
            if (evald === undefined) {
                continue;
            }
            if (!evald.splice) {
                out.push(evald);
            }
            else if (evald.length) {
                this.flatten(evald, out);
            }
        }
        return out;
    };
    Visitor.prototype.flatten = function (arr, out) {
        if (!out) {
            out = [];
        }
        var cnt, i, item, nestedCnt, j, nestedItem;
        for (i = 0, cnt = arr.length; i < cnt; i++) {
            item = arr[i];
            if (item === undefined) {
                continue;
            }
            if (!item.splice) {
                out.push(item);
                continue;
            }
            for (j = 0, nestedCnt = item.length; j < nestedCnt; j++) {
                nestedItem = item[j];
                if (nestedItem === undefined) {
                    continue;
                }
                if (!nestedItem.splice) {
                    out.push(nestedItem);
                }
                else if (nestedItem.length) {
                    this.flatten(nestedItem, out);
                }
            }
        }
        return out;
    };
    return Visitor;
}());
exports.default = Visitor;
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